1. Field of the Invention
The present invention relates to a balancing apparatus for a clothes washing machine for achieving an early attenuation of vibration of a dehydrating tub which may be produced during the initial dehydrating stage, and more particularly to a balancing apparatus for a washing machine having a plurality of balls serving as a balancer to compensate for an unbalanced rotation of the dehydrating tub.
2. Description of the Prior Art
FIG. 1 illustrates a conventional fully-automated washing machine constructed such that a dehydrating tub 12 is disposed within a washing tub 11. Washing tub 11 and dehydrating tub 12, along with a driving part 13, are suspended from a main body 14 by means of suspension rods 15, so that their vibrations are not transferred to main body 14 during the washing and dehydrating operations. In this structure, if the laundry within dehydrating tub 12 is gathered to one side, dehydrating tub 12 is severely jolted from side to side without standing upright during the rotating motion. Accordingly, in order to compensate for this unbalanced rotation of dehydrating tub 12, a balancing apparatus 16 is mounted around the upper end of dehydrating tub 12.
It is conventional to provide a balancing apparatus having a hollowed annular case body whose volume is filled to approximately 40.about.70% with liquid (for example, saline water). In recent years, however, the case body has been provided with a plurality of solid balls or combination of liquid and balls. This balancing apparatus functions to achieve an early attenuation of vibration of the dehydrating tub when the dehydrating tub is rotated under the unbalanced condition due to the gathering of the laundry to any one side therein, the balancing utilizing the phenomena that the liquid and/or the balls within the case body are moved in a direction offsetting the deviation of a centrifugal force generated by the unbalance.
FIG. 2 illustrates a conventional balancing apparatus 21, in which the interior of a case body 22 contains a plurality of solid balls 23 and no liquid. Referring to FIG. 2, case body 22 of balancing apparatus 21 has an approximately squared cross-sectional shape. In the above-mentioned balancing apparatus 21, once the dehydrating tub is rotated, balls 23 roll while in contact with both a bottom surface 22a and a radially outer peripheral wall surface 22b of case body 22, to balance the dehydrating tub.
However, according to the foregoing conventional balancing apparatus 21, since balls 23 roll in contact simultaneously both bottom surface 22a and outer peripheral wall surface 22b of case body 22, the frictional force of balls 23 with respect to case body 22 is relatively large, and thereby the time required for balancing the dehydrating tub becomes lengthened.
Furthermore, according to the foregoing conventional balancing apparatus 21, when the dehydrating tub becomes slanted due to the uneven distribution of the laundry, balls 23 within case body 22 are distributed by gravity toward the lower side to increase the mass unbalance of the dehydrating tub, and thereby to cause the dehydrating tub to be severely vibrated in the initial stage of the dehydrating phase of the washing machine.